Some sample and hold (S/H) circuitry utilizes switched capacitors. The opening and closing of switches produces nonlinear charge injection effects. These nonlinear charge injection effects can be a problem in the design of high linearity sample-and hold circuitry. Careful control over impedances seen by the sampling switches are often needed. However, careful control over impedances can be difficult to maintain due to variations in common-mode voltages and other parameters such as over process and temperature extremes.
A method and apparatus for performing voltage-mode sample and hold functions with high linearity is desired.